Field of the Invention
The present invention relates to an optical semiconductor device which integrates a semiconductor laser section and an optical waveguide section, and more particularly, to an optical semiconductor device capable of making electrical separation between a semiconductor laser section and an optical waveguide section compatible with high optical coupling efficiency.
Background Art
With a semiconductor laser, optical waveguide, optical modulator or the like integrated therein, optical semiconductor devices are becoming increasingly smaller in size and more sophisticated in performance. An integrated optical semiconductor device is known which integrates an optical active element typified by a semiconductor laser and an optical waveguide on a substrate. In such an integrated optical semiconductor device, a plurality of integrated components are generally electrically separated from each other. A p-type semiconductor layer provided on the semiconductor laser section and the optical waveguide section is not a high-resistance layer due to the necessity for supplying a current to the semiconductor laser section. Thus, an apparatus is proposed which electrically separates the semiconductor laser section from the optical waveguide section by providing a separation groove in the p-type semiconductor layer between the semiconductor laser section and the optical waveguide section (e.g., see Japanese Patent Publication No. 5463760).